1. Technical Field
The present invention relates to a water curtain forming apparatus for forming around a ship which leaks dangerous gas a water disaster prevention curtain that blocks and disperses both the gas leaking from the ship or any flames resulting from the leakage.
2. Background Art
A large quantity of flammable gas, poisonous gas or the like is often transported by marine transportation. When a ship employed for such marine transportation suffers from an accident, such as a collision with another ship, a considerable mass of gas contained in the ship leaks into the sea. In a case where the leaking gas is flammable, a large region of the sea is rendered dangerous by a prospective explosion and fire. In a case where poisonous gas leaks, the environment is damaged, which may even result in human casualties. Particularly, if such accidents happen near land, some counter measures have to be taken promptly.
Several ideas have been suggested for preventing on-land disasters by stopping the gas diffusion or accelerating gas diffusion. For low-temperature storage tanks of LNG, for instance, a liquid stoppage bank is built around the tank, and a water injecting pipe is disposed along the top rim of the bank so as to form a water curtain. The water curtain helps the leakage disperse upward, whereby the gas ascends dispersing into the air, rather than crawling over ground. Here, it should be noted that such an accident prevention measure can be applied only to a complex on the ground. This means that it cannot be employed as a water accident prevention measure since the gas stoppage bank is stationary, whereas such water accidents occur anywhere, offshore or river, and the wind changes its direction frequently and quickly on the water. In short, the conventional on-land accident prevention system described above is not suited for an accident on water due to considerations of movability, size, expense and serviceability.
It has been strongly desired under the above-mentioned circumstances to propose a water curtain forming apparatus which is movable on the water and is capable of creating a disaster prevention water curtain of a size which is sufficient to cover the accident zone.